libcamera: controls: Move Control constructor to controls.h

To avoid defining all specializations of the Control constructor
manually, move the definition of those functions to controls.h and turn
them into a single template function.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

include/libcamera/controls.h

@@ -146,7 +146,10 @@ class Control : public ControlId
 public:
 	using type = T;
 
-	Control(unsigned int id, const char *name);
+	Control(unsigned int id, const char *name)
+		: ControlId(id, name, details::control_type<std::remove_cv_t<T>>::value)
+	{
+	}
 
 private:
 	Control(const Control &) = delete;